1. Field of the Invention
The present invention generally relates to dental restoration and more specifically, to dental implants.
2. Description of the Related Art
Implant dentistry involves the restoration of one or more teeth in a patient's mouth using artificial components. Such artificial components typically include a dental implant and a prosthetic tooth, an abutment (single or multi-unit) and or a bridge or arch that is secured to the dental implant.
The dental implant is typically fabricated from pure titanium or a titanium alloy. The dental implant typically includes a body portion and a collar. The body portion is configured to extend into and osseointegrate with the alveolar bone. The top surface of the collar typically lies flush with the crest of the jawbone bone. The abutment (e.g., a final abutment) typically lies on the top surface and extends through the soft tissue, which lies above the alveolar bone. Recently, some dental implants have collars that extend above the crest of the jawbone and entirely through the soft tissue.
Implants of various tapers and with various thread profiles are known in the art. For example, U.S. Pat. No. 5,427,527 describes a conical implant design that is placed into a cylindrical osteotomy site in order to induce bone compression at the coronal aspect of the implant, i.e. at its widest end. Other thread profiles and patterns are known in the art. The most common design involves a symmetrical, V-shaped appearance such as that illustrated in U.S. Pat. No. 5,897,319. A variable thread profile is disclosed in U.S. Pat. Nos. 5,435,723 and 5,527,183 which is mathematically optimized for stress transfer under occlusal loads. U.S. Pat. Nos. 3,797,113 and 3,849,887 describe dental implants with external thread-like features having a flat shelf facing the coronal end of the implant.
While such prior art dental implants have been successful, there is a continuing desire to improve a dental implant's ability to osseointegrate with the alveolar bone and to improve the stability of the dental implant within the alveolar bone. For example, dental implants are often used to restore partially or completely edentulous patients and/or one or more teeth in the posterior region of the mouth. The posterior regions of the mouth often have less available bone height than the anterior regions. The bone density of the remaining bone after tooth loss can often be less in the posterior regions than the anterior region of the mouth.